ABSTRACT Polymer electrolytes are a key development in advancing battery technology, enabling more efficient energy storage. This study focused on developing a solid-state polymer electrolyte film by doping NH4Br with Polyvinyl Butyral (PVB) using a solution-cast method. X-ray diffraction (XRD) was employed to evaluate the amorphousness and crystallinity of the films, while Fourier Transform Infrared Spectroscopy (FTIR) confirmed complex formation between the salt and polymer. The glass transition temperature (Tg) of the electrolyte film was estimated using Differential Scanning Calorimetry (DSC). Ionic conductivity was measured through AC impedance spectroscopy, revealing that the PVB-NH4Br electrolyte doped with 30 wt% NH4Br at 30 °C had an ionic conductivity of 1.47 × 10−7 S cm−1. This conductivity followed an Arrhenius relationship, where conductivity increased with temperature. Dielectric studies showed that at low frequencies, the dielectric constant and loss were higher, while both decreased at higher frequencies. DC Wagner’s polarization technique verified that ion transport was the dominant conduction mechanism. Discharge testing of the electrolyte film using a Swagelok cell showed an open-circuit voltage (OCV) of 1.2 V and a short-circuit current (SCC) of 0.42 mA, indicating promising performance for battery applications.